Although LEDs or a halogen bulb is used as a light source for a headlamp for vehicle use, for example, LEDs which are a next-generation light source are still expensive compared with halogen bulbs. Therefore, for example, for the same car model having the same body, one of expensive LEDs and a cheap halogen bulb is selectively used according to the grade. Because the space and mounting structure for mounting a headlamp are the same in the case of the same car model, and it is desirable to make it possible to select only a light source and optical members and make them mountable, and provide commonality of a headlamp case and wirings in the body between the two types of headlamps. However, under the present circumstances, a headlamp case used for a halogen bulb and a headlamp case used for LEDs are used for headlamps for vehicle use.
Because a halogen bulb is a relatively short-life consumable part and therefore needs to be exchanged, an opening for exchanging a halogen bulb is disposed in a rear portion of the headlamp case. Furthermore, because a large optical member is used for a headlamp having a halogen bulb as a light source, the headlamp case is formed in such a way as to have a long length in an optical axis direction. On the other hand, because a halogen bulb does not have to have any lighting device because it uses a battery as a DC power supply to be able to light up, a halogen bulb does not have to have any members other than a member for power connection, and therefore a tire house is placed close to a rear side of the headlamp case and very narrow space is provided between the rear side of the headlamp case back and the car body. For example, patent references 1 to 3 disclose headlamps each having a halogen bulb as a light source. The headlamp according to patent reference 1 is constructed in such a way that in a rear opening of a headlamp case for exchange of a halogen bulb, a ring-shaped waterproof cover is disposed closely between a socket of a halogen bulb and a headlamp case to prevent water from permeating into the headlamp case. Furthermore, the headlamp according to patent reference 2 is constructed in such a way that a stop protruding edge and a slit are respectively formed in and mounted to a socket of a halogen bulb and a headlamp case so that the adhesion is improved while the waterproof performance is improved. Furthermore, the headlamp according to patent reference 3 includes a blocking member for blocking a rear opening for exchange of a halogen bulb in a headlamp case.
An LED has a long life and does not have to be exchanged, but needs to have a lighting device for making the LED light up and uses a headlamp case for exclusive use in which the lighting device is arranged. Furthermore, a connector for supplying electric power to the LED, and a connector for inputting electric power from a battery disposed outside the headlamp are disposed in the lighting device. Because there is no space for installing the connectors outside the headlamp case, the connectors are disposed inside the headlamp case together with the main part of the lighting device, and a wiring from each connector is connected to the LED or the battery via an opening formed in the headlamp case. For example, patent reference 4 discloses a structure of a headlamp having LEDs as a light source in which a headlamp case used for LEDs having a short length in the longitudinal direction of a vehicle body includes a rear opening which can be opened and closed.